“Star Vehicle” chronicles the decline of Donald Cardini, a film driver who prides himself on his love for cinema but has a tendency for violent outbursts when agitated. Tasked with chauffeuring the actors of low-budget films, along with their delicate egos, to remote shooting locations, Don finds his patience tested. Tensions reach a boiling point when Luke, an egotistical young writer and director, questions Don’s control, leading to chaos and bloodshed.